Safety closure

ABSTRACT

A safety closure formed with nested inner and outer caps has ramp lugs on facing end walls of each cap for driving engagement with each other when turned in the closure applying direction without first having to be shifted axially. This facilitates threading of the closure onto containers by automatic capping apparatus. The ramp lugs slide past one another when the outer cap is turned in the removal direction and this prevents a child from removing the closure with a simple turning of the outer cap. The outer cap has a flexible skirt which can be deflected inwardly to engage driving surfaces on the inner and outer caps. Such deflection when accompanied by a simultaneously applied torque in the removal direction, unscrews the inner cap from the container.

United States Patent [191 Cistone [4 1 Dec. 16, 1975 1 SAFETY CLOSURE [75] Inventor:

[73] Assignee: Kerr Glass Manufacturing Corporation, Los Angeles, Calif.

David R. Cistone, Lancaster, Pa.

Primary Examiner-George T. Hall Attorney, Agent, or Firm-Fitch, Even, Tabin & Luedeka ABSIRACT A safety closure formed with nested inner and outer caps has ramp lugs on facing end walls of each cap for driving engagement with each other when turned in the closure applying direction without first having to be shifted axially. This facilitates threading of the closure onto containers by automatic capping apparatus. The ramp lugs slide past one another when the outer cap is turned'in the removal direction and this prevents a child from removing the closure with a simple turning of the outer cap. The outer cap has a flexible skirt which can be deflected inwardly to engage driving surfaces on the inner and outer caps. Such deflection when accompanied by a simultaneously applied torque in the removal direction, unscrews the inner cap from the container.

5 Claims, 5 Drawing Figures U.S. Patsnt Dec. 16, 1975 3,92,328

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SAFETY CLOSURE The present invention relates generally to safety closures, and more particularly to child-safe closures having nested inner and outer caps related in a manner that requires manipulation beyond the ability of a small child to remove the closure from the container.

Child-safe closures are particularly desirable for use with containers for medicinal and poisonous liquids and compounds. In child-safe closures having inner and outer caps, the inner cap is usually threaded on the container and provides the primary seal therewith.

The outer cap is cooperable with the inner cap only after special manipulations of the outer cap in manners beyond the ability of a young child. One example of an attempt to provide a child-safe closure is disclosed in US. Pat. No. 3,027,035. The closure therein illustrated and described requires the application of substantial inward pressure against the lower half of a depending skirt of the outer cap element to effect sufficient frictional engagement with the inner cap element for applying the closure to the container. This type of closure exhibits the disadvantage that it cannot be readily applied to a container by a conventional automated capping apparatus which generally does not provide for inward compression of the depending skirts of closures when automatically assembling the closures onto containers. Rather, a conventional automated capping apparatus grasps a closure cap, moves it downwardly to engage the threaded neck of a container and merely rotates it to effect threaded engagement with the container.

Another child-safe closure is disclosed and claimed in US. Pat. No. 3,638,819, issued Feb. 1, 1972, to Gerald L. Roy, and assigned to the assignee of the present invention. The Roy closure includes interengagable means disposed adjacent the lower marginal edges of the depending skirts of the inner and outer caps which are cooperable to allow rotation of the inner cap portion through the outer cap portion to remove the closure from a container after depressing the outer cap sufficiently to overcome means normally maintaining the inner and outer cap in spaced relation. While this safety closure has proven satisfactory for its intended purpose, the present invention eliminates the requirement that the outer cap be depressed during either initial assembly onto a container or subsequent removal therefrom. The present invention provides a child-safe closure which is particularly adapted for use with automated capping apparatus.

It is therefore one of the primary objects of the present invention to provide a safety closure which is more readily applied to a container with conventional capping apparatus and yet cannot be removed from the container without manipulation in a manner beyond the ability of a young child.

Another object of the present invention is to provide a novel safety closure having inner and outer cap elements which do not require relative axial movement between the inner and outer cap elements while initially assembling the closure onto a container, but which require manipulation of the outer cap element in a manner beyond the ability of a young child to remove the closure from the container.

Further objects and advantages of the present invention, together with the organization and manner of operation thereof, will become apparent from the following detailed description of the invention when taken in conjunction with the accompanying drawing wherein like reference numerals designate like elements throughout the several views and wherein:

FIG. 1 is a perspective view illustrating a safety closure in accordance with a preferred embodiment of the present invention, the safety closure being assembled on a container shown in phantom;

FIG. 2 is an enlarged plan view of the safety closure of FIG. 1, a portion of the outer cap being broken away for purposes of clarity;

FIG. 3 is a longitudinal sectional view taken generally along the line 33 of FIG. 1, but with a capping apparatus being partially shown in phantom in cooperation with the safety closure to assemble the same onto the container;

FIG. 4 is a longitudinal sectional view generally similar to FIG. 3 but illustrating the skirt of the outer cap being compressed inwardly against the inner cap to effect removal of the closure from the container; and

FIG. 5 is a longitudinal sectional view generally similar to FIG. 3 but illustrating the overriding effect of a unidirectional drive means when the outer cap is rotated in a direction to remove the closure from the container without compressing the skirt portion thereof.

Referring now to the drawing, a safety closure in accordance with the present invention is indicated generally at 11. The safety closure 11 is shown, by way of example, as being secured on a container indicated in phantom at 13, the container 13 having an external right-hand thread 15 thereon generally adjacent the upper open end of the container. The container 13 may be made of glass, metal or a suitable plastic material for containing a liquid or solid substance. As will become more apparent hereinbelow, the safety closure 11 finds particular application with containers used for storing substances, either in liquid or solid form, which might be harmful to a young child, and where it is desirable to prevent removal of the closure by young children.

The safety closure 11 includes an outer cap 17 preferably made of plastic, and an inner cap preferably made of metal coaxially mounted and nested with each other. The outer cap 17 has an upper flat circular closed end 21 and a depending annular skirt 23 formed integral with the upper closed end 21. Preferably, at least the upper end 21 of the outer cap element 17 is transparent, although it may be desirable to make both the upper end 21 and the depending skirt portion 23 transparent.

The inner cap element 19 is formed preferably from a thin walled metal adapted for stamping, forming or spinning manufacturing techniques, and includes a generally flat upper end 25 and a depending generally annular skirt 27 formed integral therewith. The depending skirt 27 of the inner cap element is provided with a threaded surface 28 for threading onto the external thread 15 on the container 13. A compressible generally flat circular seal member 29 is snuggly received within the inner cap 19 to underlie the upper end 25 thereof for engagement with the uppermost end of the container. Upon downward threading of the inner cap 19 onto the container 13, the seal member 29 is compressed to effect a sealing relation and prevent leakage from the container in a known manner.

The outer cap element 17 is of sufficient size to re-* ceive the inner cap element 19 in nested relation therein, as shown in FIGS. 35. The outer cap element 17 has an annular lip or projection 31 extending radially inwardly from the inner surface of the annular skirt portion 23 thereof, the annular lip 31 being positioned to underlie the lower annular end of the skirt 27 of the inner cap element 19 which may be rolled as indicated at 33. In this fashion, the inner cap element 19 is captured or confined within the outer cap element 17. The skirt 23 of the outer cap 17 is formed with an increased wall thickness for its lower wall section 35 at the annular lip 31 to provide greater rigidity for the lower marginal edge of the skirt of the outer cap.

To facilitate automatic capping of the containers 13 without a substantial axial downward displacement of the outer cap 17 relative to the inner cap 19, the inner and outer caps have a unidirectional drive means 37 located between the upper flat ends 21 and 25 of the caps for rotating the inner cap 19 in the closure applying direction but for slipping and being ineffectual when a torque is applied in the reverse removal direction by a child. With a right hand thread on the container 13, the unidirectional drive means 37 is selected to unscrew the inner cap 19 with rotation of the outer cap 17 in a clockwise direction, as considered in FIG. 2; but to allow turning of the outer cap 17 in the counterclockwise direction without tuming the inner cap 19. It will be understood that if a left-hand thread is selected for the upper neck portion of the container 13, the unidirectional drive means 37 will be selected such that rotation of the outer cap 17 in a counterclockwise direction effects rotation of the inner cap 19 in a corresponding counterclockwise direction only.

The unidirectional drive means 37 includes a plurality of generally equidistantly circumferentially spaced drive lugs 39 which are preferably formed integral with and depend downwardly from the lower surface of the upper flat end 21 of the outer cap 17. The drive lugs 39 are identical in configuration and each includes a downwardly inclined ramp surface 41 which intersects a generally vertical planar drive surface 43. The lower ends or tips of the drive lugs 39 rest on the upper flat end of the inner cap 19. The drive lugs 39 on the upper end 21 of the outer cap 17 are selectively cooperable with a corresponding number of circumferentially spaced drive lugs 45 projecting upwardly from the upper end surface 25 of the inner cap 19.

The drive lugs 45 on the inner cap 19 may be formed by stamping and each includes an inclined ramp surface 47 which intersects a generally vertically disposed drive surface 49. The drive lugs 39 and 45 are adapted for cooperating engagement through their drive surfaces 43 and 49, respectively, to effect rotation of the inner cap 19 when the outer cap 17 is rotated in a clockwise direction, as considered in FIG. 2. In this fashion, the safety closure 1 1 may be readily grasped by a rotational drive member, such as partially indicated in phantom at 51 in FIG. 3, of a conventional closure applying apparatus (not shown) which is adapted to rotate the outer cap element 17 by frictional engagement therewith after the inner cap element 19 has been positioned on the upper open end of the container 13. As the lower ends of the depending drive lugs 39 are positioned for engagement with the upstanding drive lugs 45 without any substantial axial movement of the outer cap relative to inner cap, a simple rotation without axial displacement as in the prior art threads the depending skirt 27 of the inner cap onto the thread 15 on the container 13. However, if the outer cap 17 is rotated in a counterclockwise or reverse direction, as considered in FIG. 2, by means of the drive member 51 the inclined surfaces 41 and 47 or the drive lugs 39 and 45, respectively, are inclined sufficiently to the horizontal and will have insufficient frictional force therebetween to turn the inner cap. The upper end 21 of the outer cap 17 flexes sufficiently to allow its plastic lugs 39 to readily cam upwardly and over ride the lower lugs 45 without unscrewing the inner cap.

The outer peripheral surface of the depending skirt 27 of the inner cap 19 and the opposing inner surface of the depending skirt 23 of the outer cap 17 have drive surfaces thereon movable from an ineffective position in which the drive surfaces are spaced from each other to an effective position in which they are driving engagement for unscrewing the closure. A deliberate strong compressing and deflecting of the outer skirt 23 positions the drive surfaces at the effective position for turning the inner cap with turning of the outer cap. More specifically, with reference to FIGS. 25, the inner cap 19 has a drive surface 53 generally adjacent the upper end of the depending skirt 27 thereof, the drive surface 53 comprising an annular knurled surface composed of a plurality of generally vertically disposed uniform ridges or beads as shown. The annular drive surface 53 extends downwardly from the upper end 25 of the inner cap 19 a distance substantially less than one-half the longitudinal length of the inner cap. The inner peripheral surface of the depending skirt 23 of the outer cap 17 has a drive surface 55 thereon which comprises annular knurled surface similar in configuration to the annular drive surface 53. The annular drive surface 55 is normally spaced radially outwardly from the drive surface 53 and extends from the upper end 21 of the outer cap element 17 longitudinally downwardly to a position shown at 57 which is spaced slightly longitudinally upwardly from the annular lip 31. Alternatively, the drive surfaces 53 and 55 may have minimal contact with each other but only driving engagement with each other after deflection of the outer cap skirt 23. By deforming or pressing the annular skirt 23 of the outer cap element 17 inwardly to effect driving engagement between the drive surfaces 53 and 55, a simultaneous rotation of the outer cap element will effect a corresponding rotation of the inner cap element 19.

Having thus described a preferred embodiment of the safety closure 11, its operation will now be briefly reviewed. With the closure element 11 initially positioned in overlying relation to the container 13, the rotational frictional drive member 51 of the closure assembly apparatus may be brought into frictional engagement with the upper end 21 of the outer cap 17 to effect a rotational movement of the outer cap in a clockwise direction, as considered in FIG. 2. The drive lugs 39 and 45 of the unidirectional drive means turn and abut their respective drive surfaces 43 and 49 and continued rotation of the outer cap 17 will effect a corresponding rotation of the inner cap 19 thereby threading the inner cap element 19 downwardly onto the thread 15 on the container 13. After thus assembling the safety closure 11 onto the container 13, reversing rotation of the outer cap 17 through a light grasping of the outer cap will be ineffective to remove the inner element from the container 13 due to the overriding of the inclined surfaces 41 and 47 of the driving lugs forming the unidirectional drive means.

To remove the safety closure 11 from the container 13, the depending annular skirt 23 of the outer cap element 17 must be compressed radially inwardly adjacent the upper end surface 21 thereof, as shown in FIG. 4

with a predetermined force generally greater than a child will apply trying to merely twist the closure from the container. The applied inward force on the skirt 23 must be sufficient to deform the skin 23 and to flex inwardly the drive surfaces 55 to engage drive surfaces 53 of the inner cap 17. After effecting such interengagement of the drive surfaces 53 and 55, rotation of the outer cap in a counterclockwise direction, as considered in FIG. 2, will effect removal or release of the inner cap from the thread of the container 13. Thus it will be seen that the wall strength of the depending skirt 23 of the outer cap 17 is selected such that the depending skirt 23 cannot be manually compressed inwardly sufficiently to effect such interengagement be tween the drive surfaces 53 and 55 by a young child. In this fashion, the safety closure 11 cannot be removed from the container 13 by a young child with resulting access to the interior of the container. The safety closure 11 thus serves to provide a safe means for closing and sealing the open end of the container 13 to prevent access by children to any harmful materials as may be stored in the container.

The safety closure 11 is applied to a container by conventional closure applying apparatus without the necessity of the apparatus causing a substantial axial movement of the outer cap relative to the inner cap preparatory to applying a torque in the applying direction. Thereafter, the safety closure can only be removed from the container upon which it is secured by a simultaneous substantial inward deflection of and a torque application to the depending skirt of the outer cap.

Having thus described a preferred embodiment of the present invention, it will be understood that changes and modifications may be made therein without departing from the invention in its broader aspects. Various of the features of the present invention are set forth in the following claims.

What is claimed is:

l. A safety closure for a container comprising: an inner cap having an upper end and a generally cylindrical skirt extending downwardly from the periphery of the outer edge of the upper end, said inner cap being adapted to be threadably secured on said container for effectuating a closure thereof, said upper end having a plurality of upstanding lugs located on the upper surface thereof and an outer cap coaxially aligned with and generally overlaying said inner cap, said outer cap having an upper end and a generally cylindrical skirt extending downwardly from the periphery of the outer edge of its upper end, a plurality of downwardly projecting lugs located on the inner surface of said outer cap, said lugs on said inner and outer caps being aligned in a substantially common plane and having substantially vertically extending drive surfaces for abutting and for causing said inner cap and said outer cap to rotate in unison when said outer cap is rotated in a closure direction, said lugs having inclined ramp surfaces for abutting and sliding over each other when said outer cap is rotated in an unlocking direction so that rotation of said outer cap in an unlocking direction does not rotate said inner cap, said lugs on at least one of said caps touching the end wall of said other cap to hold said flat end portion of said outer cap against downward movement, said drive lugs riding over each other to flex said flat end portion upwardly when said outer cap is turned in said reverse direction, cooperable drive surfaces formed on said skirts of said inner and outer caps, said outer cap skirt being made of aresilient material and adapted to be resiliently deformed inward by hand applied compression for causing said drive surface on said outer cap skirt to move from an ineffective position to an effective position for driving engagement with the drive surface on said inner cap skirt, said inner and outer caps rotating in unison when a torque is applied in the unlocking direction and said outer cap skirt is deformed inwardly to said effective position to cause driving engagement between said drive surfaces.

2. A safety closure as defined in claim 1 wherein said drive surfaces on said inner and outer caps comprise spline surfaces.

3. A safety closure as defined in claim 2 wherein said spline drive surface on said inner cap is disposed adja cent the upper flat end thereof and extends longitudinally along the annular skirt portion thereof a distance less than one-half length the longitudinal of said annular skirt portion.

4. A safety closure as defined in claim 1 wherein said inner cap is metallic and wherein at least the upper end of said outer cap is made of transparent plastic.

5. A safety closure as defined in claim 4 wherein the upper outer surface of said end portion of said inner cap has operating instructional indicia thereon visible through said end portion of said outer cap. 

1. A safety closure for a container comprising: an inner cap having an upper end and a generally cylindrical skirt extending downwardly from the periphery of the outer edge of the upper end, said inner cap being adapted to be threadably secured on said container for effectuating a closure thereof, said upper end having a plurality of upstanding lugs located on the upper surface thereof and an outer cap coaxially aligned with and generally overlaying said inner cap, said outer cap having an upper end and a generally cylindrical skirt extending downwardly from the periphery of the outer edge of its upper end, a plurality of downwardly projecting lugs located on the inner surface of said outer cap, said lugs on said inner and outer caps being aligned in a substantially common plane and having substantially vertically extending drive surfaces for abutting and for causing said inner cap and said outer cap to rotate in unison when said outer cap is rotated in a closure direction, said lugs having inclined ramp surfaces for abutting and sliding over each other when said outer cap is rotated in an unlocking direction so that rotation of said outer cap in an unlocking direction does not rotate said inner cap, said lugs on at least one of said caps touching the end wall of said other cap to hold said flat end portion of said outer cap against downward movement, said drive lugs riding over each other to flex said flat end portion upwardly when said outer cap is turned in said reverse direction, cooperable drive surfaces formed on said skirts of said inner and outer caps, said outer cap skirt being made of a resilient material and adapted to be resiliently deformed inward by hand applied compression for causing said drive surface on said outer cap skirt to move from an ineffective position to an effective position for driving engagement with the drive surface on said inner cap skirt, said inner and outer caps rotating in unison when a torque is applied in the unlocking direction and said outer cap skirt is deformed inwardly to said effective position to cause driving engagement between said drive surfaces.
 2. A safety closure as defined in claim 1 wherein said drive surfaces on said inner and outer caps comprise spline surfaces.
 3. A safety closure as defined in claim 2 wherein said spline drive surface on said inner cap is disposed adjacent the upper flat end thereof and extends longitudinally along the annular skirt portion thereof a distance less than one-half length the longitudinal of said annular skirt portion.
 4. A safety closure as defined in claim 1 wherein said inner cap is metallic and wherein at least the upper end of said outer cap is made of transparent plastic.
 5. A safety closure as defined in claim 4 wherein the upper outer surface of said end portion of said inner cap has operating instructional indicia thereon visible through said end portion of said outer cap. 